According to prior art, a device is connected to a network that provides services such as audio and/or video services. The network transporting these services can include various equipments such as transmitters, modulators, demodulators, routers, switches, DSLAMs (Digital Subscriber Line Asynchronous Multiplexer), modems. These equipments are interconnected by wired and/or wireless connections that may influence the reception quality of a device. The reception quality may in turn influence the quality of user experience of a user using the device; the quality of user experience being the quality experienced by the user of the device when rendering of the service. A difference is made between quality of reception and quality of user experience. For example, when a device receives a service subject to the loss of a relatively small number of packets, but the packets that are lost concern I (Intra) type packets in a H.264 encoded stream, the impact on the service rendering can be important, since the decoder in the device can not use other packets that depend on the I type packets such as B or P type packets, even when these packets are correctly received. Then, the loss of a relatively small number of packets can cause the apparition of visible artifacts such as macro-blocks. As for Quality of Service, Quality of Experience is measurable. For example, quality of experience can be measured in channel change time and the number of macro-blocks in a video per time-entity, or the number of drop-outs in an audio rendering.
Throughout this document, the terms QoS, for Quality of Service, which corresponds to quality of reception and QoE, for Quality of Experience which corresponds to quality of user experience are being used.
Throughout the rest of this document, the general term quality statistics is used, that comprise QoS and QoE statistics.
Due to differences in the network path that a same service provided to different devices traverses, different devices can be subject to different QoS and QoE. In addition, for a same QoS, different user devices can have different QoE due to differences in the quality of the rendering or the decoding of the device.
Therefore, methods exist that allow a provider of services to devices to acquire statistics related to the QoS/QoE of digital audio and video services. For example, document TR-135 Issue 1 (TR for Technical Report, a series of documents issued by the Broadband Forum, formerly DSL Forum), specifies a mechanism to monitor QoS and QoE of an IPTV (Internet Protocol TeleVision) service. TR-135 is part of the TR-069 series of specifications, where TR-069 specifies a protocol that allows the remote management of devices.
The drawback of the prior art, represented for example by documents TR-069 and TR-135 Issue 1, is that the prior art allows collecting QoS monitoring statistics for IPTV networks but these statistics are subject to the behavior of the user of the device of which statistics are collected. There is no way to get quality statistics of device during a period of non-activity of the device, and thus it is not possible to get quality statistics during a period that is free of any user action. Furthermore, there is no way to get quality statistics over a same time period from several devices.